Functionally graded materials (FGMs) in which the elemental composition intentionally varies with position can be fabricated using directed energy deposition additive manufacturing (AM). This work examines an FGM that is linearly graded from V to Invar 36 (64 wt% Fe, 36 wt% Ni). This FGM cracked during fabrication, indicating the formation of detrimental phases. The microstructure, composition, phases, and microhardness of the gradient zone were analyzed experimentally. The phase composition as a function of chemistry was predicted through thermodynamic calculations. It was determined that a significant amount of the intermetallic σ-FeV phase formed within the gradient zone. When the σ phase constituted the majority phase, catastrophic cracking occurred. The approach presented illustrates the suitability of using equilibrium thermodynamic calculations for the prediction of phase formation in FGMs made by AM despite the nonequilibrium conditions in AM, providing a route for the computationally informed design of FGMs.

The skull of the extinct rhinoceros Stephanorhinus kirchbergensis (Jäger, 1839) was discovered in the Chondon River valley (Arctic Yakutia, Russia) during the summer of 2014. This is the first find of Stephanorhinus above the Arctic Circle, expanding significantly the known geographic range of the genus. 14C dating and geologic evidence indicate that the skull dates to between 48,000 and 70,000 yr, corresponding to Marine Oxygen Isotope Stage 4/3. It is thus among the latest records of this species. To explore the evolutionary and natural history of this relatively unknown animal, we performed morphological, dietary, and genetic analyses. Phylogenetic inference based on a complete mitochondrial genome sequence confirms the systematic placement of Stephanorhinus as most closely related to the extinct woolly rhinoceros, Coelodonta. Food remains in the fossas of the cheek teeth, identified as Larix, Vaccinium, Betula sp., Aulacomnium, and dicotyledonous herbs and grasses, suggest a mixed feeder’s diet. Microwear analysis suggests that, during the last months of its life, this individual fed predominantly on leaves and twigs. The habitat of Stephanorhinus comprised grassland and open woodland that were characterized by moist and cold climate conditions, similar to those in the region today.

Regulatory impact analyses (RIAs) weigh the benefits of regulations against the burdens they impose and are invaluable tools for informing decision makers. We offer 10 tips for nonspecialist policymakers and interested stakeholders who will be reading RIAs as consumers.

1. 1. Core problem: Determine whether the RIA identifies the core problem (compelling public need) the regulation is intended to address.

2. 2. Alternatives: Look for an objective, policy-neutral evaluation of the relative merits of reasonable alternatives.

3. 3. Baseline: Check whether the RIA presents a reasonable “counterfactual” against which benefits and costs are measured.

4. 4. Increments: Evaluate whether totals and averages obscure relevant distinctions and trade-offs.

5. 5. Uncertainty: Recognize that all estimates involve uncertainty, and ask what effect key assumptions, data, and models have on those estimates.

6. 6. Transparency: Look for transparency and objectivity of analytical inputs.

7. 7. Benefits: Examine how projected benefits relate to stated objectives.

8. 8. Costs: Understand what costs are included.

9. 9. Distribution: Consider how benefits and costs are distributed.

10. 10. Symmetrical treatment: Ensure that benefits and costs are presented symmetrically.